Line REPL tool rows: remaining rendering after ADR 0019

[justrach]

Problem

ADR 0019 made tool rows one interpreted line instead of live bash / JSON envelopes. That part works:

  ✓ read  src/version.zig  full · 72 lines
  ✓ read  docs/architecture.md  lines · 161 lines

What is still wrong:

1. mode=lines is tautological. lines · 161 lines prints the CodeDB mode name as if it were a decision. full · 72 lines is only slightly better. The user-relevant fact is architecture.md · 161 lines.
2. The wall of prose still follows. After those two rows the model dumps a full architecture essay (layout, branch vs main, how the watcher works). The chrome cannot stop model narration; there is no fold/expand on the line REPL, so the transcript still is not something you can stare at all day.
3. No progressive disclosure. Raw output is /debug or the TUI fold only. Enter/click to expand a one-liner was part of the original sketch and is not built.
4. JSON interpretation is still mode-leaky. interpretJson surfaces mode verbatim (section, outline, lines, full) instead of a noun the user would miss (161 lines, outline).

Not this issue

Do not bring back live bash dumps, command-as-detail, or the {"ok":true,"file":...} envelope. Those are the regressions ADR 0019 exists to prevent.

Wanted

  ✓ read  version.zig · 72 lines
  ✓ read  architecture.md · 161 lines

and a way to open the raw result on demand. Model essays are a separate prompt-policy question; this issue is the harness chrome.

[justrach]

The mode-leak half is fixed in #642: interpretJson now interprets a content-bearing read as 161 lines — never lines · 161 lines or full · 72 lines; outline/symbol stay nouns. Row reads ✓ read architecture.md · 3 lines.

Still open from this issue: progressive disclosure (enter/click to expand a one-liner). Raw output remains at /debug and spilled results badge ⇢ N KiB handle, per ADR 0019.

[justrach]

Completed on release/v0.0.279 in 9179156. Line-REPL tool rows now retain only hidden raw detail in a bounded 16-entry disclosure history, show ↵ raw when there is something to inspect, and empty Enter reveals unseen results newest-first. The expanded bytes are terminal-sanitized; automatic live dumps remain off and /debug is unchanged. Verified by tier 1: 1,703 core tests, 445 TUI tests, all 17 PTY probes, reachability, build, invariants, and SDK drift.